An aid worker has died in Borno State after catching the new coronavirus; his employer Médecins Sans Frontières said, raising fears that the infection has found a foothold in the troubled region.

The government and aid groups were trying to trace anyone who had come into contact with the man before he died; the U.N. Humanitarian Coordinator in Nigeria, Edward Kallon, said on Monday, April 20.

The case was the first confirmed in Borno; a state at the epicentre of a decade-long insurgency that has killed thousands and forced an estimated 1.7 million to flee, many into crowded displacement camps.

The Nigeria Centre for Disease Control (NCDC) said late on Sunday it had recorded 627 cases of the novel coronavirus across the country.

Up to now, the bulk of cases have been reported in Lagos; on the coast more than 1,500 km away from Borno’s main city Maiduguri.

The United Nations said the aid worker was a nurse who had not travelled outside the state.

“Our dear colleague died on 18 April in Maiduguri. Post mortem test results indicated that they were positive for COVID-19,” MSF said in a statement, referring to the disease caused by the coronavirus.